The 445814 is a Humidity Alert Hydro-Thermometer that has programmable %RH audible and visual alarms that alerts you when humidity exceeds the set limit. Large LCD simultaneously displays temperature, humidity and dew point. It measures humidity from 10 to 99% and temperature from 14 to 140F (-10 to 60C). This meter has a basic accuracy of 4%RH and 1.8F/1C and a rear calibration pot for humidity and temperature. Max/Min with reset function stores and recalls the highest and lowest readings recorded. Comes complete with built-in stand, wall bracket and AAA battery.